Offset mechanism for printing-machines



(No Model.) 3 SheetsSheet 1.-

W. SCOTT. OFFSET MECHANISM FOR PRINTING MACHINES.

Patented May '7, 1889.

Lithographer, Washington D, C.

(No Model.) 3 Sheets-Sheet 2.. W. SCOTT. OFFSET MECHANISM FOR PRINTINGMACHINES;

Patented May 7, 1889 (No Model.) 3 Sheets-Sheet 3.

W. SCOTT.

OFFSET MECHANISM FOR PRINTING MACHINES.

Patented May '7, 1889.

ET X 1 N. PEYERS Pmlu'Limognphar. Washington. D. C.

UNITED STATES PATENT OFFICE.

WALTER SCOTT, OF PLAINFIELD, NEW JERSEY.

OFFSET MECHANISM FOR PRINTING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 402,772, dated May 7,1889.

Application filed April 17, 1888.- Serial No. 270,935. (No model.)

To all whom, it may concern.-

Be it known that LWALTER SCOTT, of Plainfield, in the county of Unionand State of New Jersey, have invented an Improvement in OffsetMeohanismforPrinting-Machinespf which .the following is a specification.

I make use of an offset-web and rollers for receiving the same, theparts being arranged so that the web is wound up automatically, and theroller which is full is passed into the place that had before beenoccupied by the roller from which the web had been drawn, and theoffsetweb is then passed through the press in the opposite direction andwith the reverse side to the printed matter, so that the ink dries andoffsets are prevented.

In the drawings, Figure 1 is a vertical section of a portion of aprinting-press with my improvement applied thereto. Fig. 2 is anelevation of a portion of the frame, the winding-roller and itssupporting-arm, and the tension device. Fig. 3 is a section of thefrictional gear at the end of the winding-cylinder. Fig. 4 is a plan atone end of the winding-rolls, and Fig. 5 is a diagram of a modificationin the support for the wind-up roll.

R R are the type-cylinders, and Q Q the impression-cylinders. If thereare illustrations to be printed, the plates or blocks are to be placedupon the cylinder R. The cylinders are preferably arranged as shown, sothat the second impression-cylinder is below the first, and the web ofpaper to be printed passes beneath the cylinder R, over theimpressioncylinder Q, and around between the cylinders Q Q, and betweenthe second type-cylinder, R ,and the second impression-cylinder,Q', andfrom these the web of paper is conveyed by the tapes 28 to the cutter-cylinders S S, where the web is perforated. From thence the web ofpaper is conveyed by the tapes 3O 31 to the nipping-rollers K L, and thelatter act in connection with said tapes 3O 31 to separate the sheets atthe places perforated in the web by the cutter-cylinders S S. The belts3O 31 then convey the separated sheets to the folding or deliverydevice. The means for inking the type-cylinders are not shown in thedrawings, and a reference is hereby made to my-application for patent,No. 251,872, for a description of an arrangement of rollers that may beused for inking the cylinders R R.

The paper, as it passes off from between the type-cylinder R andoifsetwveb, is below such web; hence it falls therefrom by gravity uponthe belts or tapes 28, which is a great convenience, especially inentering a fresh 'Web of paper.

The offset web 40 is rolled upon the roller M, the shaft of which restsin the brackets 41, secured to the side frames of the press, and thereis a friction-strap, 42,'lever, and weight 43 to apply to the roller Mthe necessary friction to prevent the roller M revolving too rap idly. 7The offset-web passes over the rollerN directly to the guide-roller 45,and thence around the impression-cylinder Q, as shown in Fig. 5, or elseit may pass up over the guide-rolls 46 47 previous to reaching suchroller 45, and after the offset-web has passed around theimpression-cylinder Q it passes over the winding-cylinder P and is woundupon the roller N, that is received into jaws at the ends of the arms Nupon the shaft N There is a frictional clamp, N applied to a disk uponthe shaft N that is adjustable by the screw 50 and prevents the arms Nswinging in the line of the dotted arc, except as the offset-webaccumulates by being wound upon the roller N, and I remark that thewinding-cylinder P is to be driven in such a manner as to maintain aslight tension on the tympan-sheet, which may be accomplished by theactuating-power moving slightly faster than the travel of theoffset-web, so as to apply a constant strain to said tympan; or thecylin der P can be slightly larger than the pitchline of the gear-wheel51, by which it is driven from the gear 64 on the shaft of the cylinderQ, Fig. 5; or the frictional driving mechanism may be of any desiredcharacter;'or the cylinder P may slip upon the paper as it is movingslightly faster. With this object in view the gear-wheel 51' at the endof the shaft 52 of the winding-cylinder is pressed against afriction-disk, 53, by an adjustable spring, 54, and this gear-wheel 51is to .be revolved slightly faster than the cylinder P, so that thecylinder P is driven by the friction between wheel 51 and disk 53, andthe offset-web will always be kept under a slight strain and it will bepulled off the roller M by the impression-cylinder Q, and suchoffset-web will intervene between the printed surface of the web and theimpression-cylinder Q, so as to receive any offset from the printedsurface.

The offset-web being drawn through the press by the action of theimpression and type cylinders, its speed of movement is uniform, andsuch speed is not influenced by the speed of the wind-up cylinder; hencethe speed of the latter can be slightly greater to prevent any slacknessor wrinkles in the offset-web as wound up; and. by using the separatewinding-cylinder l? the offset-web is wound up with the offset sideoutwardly, but when the offset-web is being drawn off the roll theinnerside is presented for the offset; hence the alternate sides of theoffset-web are used to receive the ofisets from the impressions.

The roller N is revolved by contact with the winding-cylinder P, and itwill be observed that as the diameter of the offset-web increases uponthe roll N it decreases upon the roll M;hence when the offset-web hasbeen all drawn off the roll M the roll N will be of the largest diameterand occupy the position shown by dotted lines, Fig. 1, and it is onlynecessary to open the journal-bearing 41 and take out the roll M andturn aside the friction-strap and then swing the crank-arms N and turnthe rock-shaft N so as to bring the projecting ends of the shaft of theroll N upon the inclined upper surface of the brackets 41, and the rollN containing the offsetweb will roll down to place in the bearings uponthe brackets 41, and the end of the offset-web is then to be passedbeneath the roll 45 around the impression-cylinder Q andwinding-cylinder P to the roll M, which is now placed into the forkedends of the arm N, (in place of the roller N,) the arms N and shaft Nbeing then turned so as bring the roller carried by it into contact withthe offset-web upon cylinder P, so that the winding operation commenceswhen the press is again started.

I11 changing the offset-Web and rolls itwill be apparent that the presscan be stopped. and the empty roll removed before the last end of thesheet reaches the roll. The full roll of oifseteweb is now transferredto the brackets 41, and the web of paper out across, leaving a shortlength in the press, and then the end of the web can be pasted upon therear end of the offset-web in the press, so as to be drawn through thepress when again started.

By my improved arrangements the offsetweb is turned over each completemovement thereof, so that one side thereof receives the offset whenrunning through the press, and then the other side receives the offsetwhen the web is run through the second time, and

slide back with the roller and its shaft as the offset-web increases indiameter, as shown in Fig. 5. In either form the roller upon which theoffset-web is wound is moved laterally toward the bearings 41 by theaccumulation as the winding progresses, so that the roller has to bemoved but a small distance when the roll is transferred.

I claim as my invention- 1. The combination, with the type-cylinders R Rand impression-cylinders Q Q, of the winding-cylinder P, a tympan oroffset sheet, two rollers for the same, fixed bearings for one of therollers, arms N and shaft N for the other roller, and a frictionalmechanism upon the shaft N for insuring the proper pressure between thewinding-cylinder and the roll as the tympan-sheet is wound up,substantially as set forth.

2. The combination, with the offset-Web and the rolls M N, ofthebrackets 41, having inclines upon which the journals of the roll (Mor N) are received and boxes into which the journals are received, andthe arms N or equivalents for moving the full roll to the inclines,substantially as specified.

3. The combination, with the printing and impression cylinders, of anoffset-web passing around the impression-cylinder, one roll for theofiset-web and stationary bearings for the same, a second roll on whichthe offset-web is wound, and moving bearings for the same that are movedlaterally by the accumulation of the offset-web as'wound up, so that theroll and its bearings are carried bodily toward the stationary bearings,to be subsequently transferred thereto, as set forth.

4. The combination, with the offset-web and the rolls on which the sameis wound, of a roller or cylinder for drawing off the said web and awind-up cylinder and a frictional connection to the motive power,whereby the wind-up cylinder causes a constant strain to keep theoffset-web sufficiently tight, substantially as set forth.

5. The combination, with the printing and impression cylinders, of anoffset-web pass ing in above the impressioncylinder and wind-upmechanism for drawing the web up from below the impression cylinder, andmechanism for receiving and cutting the web of paper as it falls awayfrom the oifsetweb, substantially as specified.

6. The combination,with'the rolls for the offset-web, and the printingand the impression cylinders, of a winding-cylinder against which theweb as it is wound up into a roll rests, and mechanism for rotating thewinding-cylinder so that its surface is moved slightly faster than theweb for keeping the latter under tension as rolled up, substantially asspecified.

Signed by me this 13th day of April, 1888.

\VALTER SCOTT.

Witnesses:

GEo. T. PINCKNEY, WILLIAM G. Mom.

